In biological classification, the order isa taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. The well-known ranks in descending order are: life, domain, kingdom, phylum, class, order, family, genus, and species, with order fitting in between class and family. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. a taxonomic unit in the rank of order. In that case the plural is orders.
